Tufting is widely used to support and strengthen upholstered articles, such as mattresses. Approximately 40% of all mattresses sold in the United Kingdom in 2001 were tufted.
Tufting typically involves the insertion of an elongate flexible element such as a tape or string interconnecting a pair of toggles (the whole hereinafter referred to as a “tuft”) through a mattress so that one toggle resides on either side of the mattress. The mattress is usually compressed during insertion of the tuft and allowed to expand once the tufting process has been completed. Since the length of the tuft is marginally less than the depth of the mattress, the region of the mattress near the tuft remains slightly compressed following expansion of the mattress after insertion.
It is common for a washer, often made of felt or a similar compressible material, to be located intermediate the toggle and the outer surface of mattress on each side of the mattress. Such washers reduce wear caused by rubbing of toggles over the surface of the mattress and prevent toggles from being pulled into the mattress. A further advantage of using washers is that, due to their compressible nature, each toggle can sink down into its associated washer thereby reducing the extent to which the toggle protrudes from the mattress surface thus increasing the aesthetic appeal and comfort of the mattress.
The tufting process is normally carried out manually by a worker standing adjacent a mattress with a tuft insertion needle and a series of separate tufts and washers. A tuft and washer are loaded onto the needle, the needle forced through the mattress and subsequently withdrawn to be reloaded ready for insertion of the next tuft. The washer loaded onto the needle remains on the side of the mattress nearest the worker. A second washer must then be manually inserted in between the toggle and the surface of mattress on the opposite side of the mattress. The process is therefore slow, labor intensive and inefficient. Furthermore, the repetitive nature of the work has lead to some workers developing repetitive stress injury (RSI).
There have recently been attempts to automate parts of the tufting process. European Patent Application No. EP0844210A2 (RESTA S.R.L) discloses an apparatus for fitting quilting braces, or tufts, to mattresses. A tuft insertion needle is supported on a frame to one side of the mattress and a string of washers is supported in a channel aligned with the needle on the opposite side of the mattress. A pneumatic jack is used to force the needle (with a tuft and washer loaded) through the mattress and into the leading washer of the string. The tuft is released from the needle, the needle retracted and the leading washer from the string drawn against the side of the mattress. While this apparatus goes someway towards automating the tufting process, individual tufts and washers must be manually loaded onto the needle each time a tuft is to be inserted, significantly reducing the efficiency of the process.
A further attempt to automate the tufting process is disclosed in European Patent Application No. EP1167279A2 (WHALEY). A device and method are described for tufting upholstery units using individual tufts automatically separated from a continuous string of tufts each time one is to be inserted. Reference is made to a support (i.e., a washer) feed means. From FIG. 15 of this document it appears that individual washers are fed, possibly under gravity, to the insertion needle. Since washers are typically made from a soft, flexible material, such as felt, it will be readily apparent to those skilled in the art that in order to overcome the practical difficulties inherent in individually feeding such washers a great deal of technical expertise would be required. However, since very few technical details are provided it is unclear exactly how this feature surmounts these problems and contributes to improving the efficiency of the overall tufting process.
An object of the present invention is therefore to provide a more efficient method of automatically tufting an upholstered article. A further object of the present invention is to provide a method of automatically feeding individual upholstery washers to an upholstery tufting apparatus so as to increase the efficiency of tufting an upholstered article.
There is a general need in the industry to provide an improved tufting method and apparatus. The present invention satisfies this need and provides other benefits and advantages in a novel and unobvious manner.